Apparatus for retaining blanks in working machines

ABSTRACT

According to the present invention a plurality of blanks (2) to be surface machined in working machines are placed side by side and fixed in a frame (1), open at both sides, in such a way that the blanks (2) can be machined at least at two sides while the fixation of the blanks (2) in the frame (1) is maintained. The blanks (2) are fixed tensionless in the frame (1) in such a position where the blanks bear against the frame sides on which the machining forces work during machining. The frame (1) with the blanks (2) fixed therein is first kept clamped with one side (4) resting against a machine support (6), while the portions (17) of the blanks (2) at the opposite side (5) are machined. After that the frame (1) is turned in such a way that the blanks (2) with its machine portions (17) rest against a support (6) consisting of a plane magnet plate, whereupon the blanks (2) are machined on the side (18) facing away from said support (6). 
     The frame (1) for carrying out the method is formed at one side (4) in such a way that the blanks (2) fixed therein are available for machining from said side (4) although they are to be situated inwardly of the plane of the side (4), since this plane is to be kept fixed against a plane support during working of the fixed blanks (2) from the opposite side (5) of the frame (1) outside the plane of which side (5) the blanks (2) are intended to reach.

The present invention relates to a method of surface machining blanksinto shanks for carbide tips or the like in working machines, such asmill cutters, in which method a plurality of blanks are placed side byside and fixed with or without shims therebetween, in a frame open atboth sides, and in which method the frame is clamped in variouspositions relative to the machining tools of the working machines forprocessing the blanks therein so that machining of the blanks iseffected at least at two of the sides thereof while the fixation of theblanks in the frame is maintained. Characteristic of the method is thatthe blanks are fixed in a substantially tensionless manner in the framein such a position, where the blanks bear against the frame sides onwhich the machining forces work during machining, that the frame isfirst held clamped with one side resting against a machine support,while the portions of the blanks on the opposite side are machined, thatthe frame then is turned so that the blanks with their machined portionsrest against a support consisting of a plane magnet plate, whereupon theblanks are machined on the side facing away from said support. Since theframe, with the blanks fixed without tension, is turned after the firstmachining operation so that the machined plane blank portions will bebrought into plane engagement with the plane magnet plate, which securessafe retention of the blanks, it is possible to obtain a most exactworking of the final shape of the shanks in the frame. Thus, theinvention permits obtaining products of angular and dimensional accuracyat a reasonable cost.

The invention is also directed to an apparatus for retaining a pluralityof blanks for shanks for carbide tips and the like in working machinessuch as mill cutters. The apparatus comprises a frame of preferablymagnetic material, such as steel, in which the blanks are to be placedside by side and fixed. The frame is formed in such a way that theblanks can be machined from two sides without their fixation in theframe being changed. Characteristic of the apparatus is that the frameat one of its sides is so formed that the blanks fixed therein areavailable for machining from said side although they are intended to besituated inwardly of that plane of the side which is adapted to be keptfixed against a plane support during working of the fixed blanks fromthe opposite side of the frame outside the plane of which side theblanks are intended to reach.

The invention will be more fully described hereinafter with reference tothe accompanying drawings which illustrate both the method and theapparatus and also some blanks adapted for machining and in which:

FIGS. 1-3 show by a way of example a frame in three directions at rightangles to each other;

FIGS. 4 and 5 are respectively a top and an end view of a washer for theframe;

FIGS. 6-9 are top views of frames with blanks clamped therein;

FIGS. 10 and 11 illustrate two successive machining moments withretained fixation of the blanks in the frame;

FIG. 12 illustrates machining of the blanks by means of an end facemill; and

FIGS. 13-15 show three different blanks for shanks for carbide tips,which blanks can be machined in accordance with the present invention.

The apparatus of the invention consists of a frame 1 in which the blanks2 are to be placed side by side and fixed with or without shims 3therebetween. The frame 1 with the blanks 2 is, in turn, adapted to beclamped in various positions relative to the machining tools in variousmachines for processing the blanks 2 therein. Thus, machining of theblanks 2 can be effected at least at two of the sides thereof while thefixation of the blanks in the frame 1 is maintained. A rapid andeconomic production is obtained since the frame 1 allows simultaneousmachining of a plurality of blanks 2 and the blanks 2 can maintain thesame fixed position in the frame during two or more machiningoperations.

As appears from FIGS. 1-3 and FIGS. 10 and 11, the frame 1 is so formedat its side 4 that the blanks 2 fixed therein are available formachining from said side 4 although they are intended to be situated orrecessed inwardly of the plane of the side 4, since said side plane 4 isto be kept fixed against a plane support 6 during working of the fixedblanks 2 from the opposite side 5 of the frame 1 outside the plane ofwhich side 5 said blanks 2 are intended to reach.

The frame 1 is of rectangular shape. In most cases the frame 1 willinclude two pairs of opposed, parallel frame sides 7-10. In certaincases, however, the frame 1 must have one open frame side, as isapparent from FIG. 9. This will make it possible to machine the endportions of the blanks 2 at the open frame side.

The frame 1 of U-shaped cross-section, the width of the branches 11 and12 being smaller than the width of the frame sides 7 and 8. As appearsfrom FIGS. 10 and 11 the branches 11 and 12 may be provided with slots13 on their inside for corresponding projections 14 at the edges of awasher 15. The slots 13 and the projections 14 are formed so that a playis provided therebetween.

The blanks 2 are fixed in the frame 1 in such a way that they willextend and reach outside the side 5 of the open frame 1, while they arerecessed and spaced inside the side 4. First the blanks 2 are machinedon the side corresponding to the side 5. To this end the frame side 4should rest against the support 6 which preferably is a magnet plate.Thus the magnet plate 6 retains the plane frame 1, which of courseimplies that the frame consists of a magnetic material, such as steel.Alternatively the support 6 may be a plate having a number of suckingmeans which enter into function when an object rests against it. Thesupport 6 may also consist of a common table for workpieces to which theframe 1 is clamped in the usual manner.

It is important that the blanks 2 should not be influenced by themagnetic force from the magnet plate 6 since this can produce tensionsin the blanks 2 which are not entirely planar. The blanks 2 thereforeare fixed in the frame 1 in such a way that there will be a gap betweenthe blanks 2 and the magnet plate 6 when the frame 1 is clamped againstit. The gap between the blanks 2 and the magnet plate 6 is filled outwith a specific plate which consists of the washer 15 described above.

When the blanks 2 are placed in the frame 1 they are knocked downtowards a plate corresponding to the washer 15 and fixed. The fixationshould not take place with any considerable force and therefore thefastening means 16 may consist of screws which are tightened by hand.The fastening means 16 may likewise consist of hydraulic or pneumaticcylinder-piston means or the like with adjustable tensional force. Thusthe blanks 2 are fixed in an at least substantially tensionless mannerin the frame 1. The fixation, however, is such that the blanks 2 will besafely secured in position during machining. Thus the blanks 2 willbear, with or without their shims 3, against the frame sides on whichthe machining forces work during the machining operation.

When the blanks 2 are machined on the side 17 corresponding to the side5, the frame 1 is turned so that the machined side 17 will rest againstthe support 6 of the working machine. The support can and should consistof a magnet plate 6 since the side 17 of the blanks resting against thesupport now is entirely planar. The blanks 2 can now be machined on theside 18 facing away from the support 6 so that the sides 17 and 18become plane-parallel.

In case the blanks 2 are to assume parallelepipedic shape, the blanksturn through 90° in the frame so that the machined sides 17 and 18 willbear against each other. The other two sides 19 and 20 are now ready formachining in the frame 1 or in another frame. Considering the fact thatburrs may arise during machining of the first sides 17 and 18, the frame1, at least at one end, and the washer 15, at its upper side, areprovided with grooves 21 placed where the transitions between thedifferent blanks 2 can be expected to be situated.

As indicated above, the fastening means 16 are not to be acted upon byany great force, because the machining of the blanks 2 in the frame 1 iscarried out in such a way that it contributes to the retention, as shownin FIG. 12. The circle 22 represents the outer contour of an end facemill. The centre axis thereof is situated inside the centre line 23 forthe blanks 2 in the frame 1. The centre axis moves along the line 24 tothe right with respect to the figure and the mill cutter rotatesanticlockwise in the direction of the arrow. The blanks 2 and,consequently, the frame 1 are thus pressed against the stationary sides25 against which it rests.

FIGS. 13-15 show some blanks 2 which can be surface machined inaccordance with the invention. As many as six different surfacemachining operations can be carried out on these blanks with one and thesame fixation. The blanks according to FIGS. 14 and 15 must be providedwith shims 3 as they are placed in the frame 1 with the sides shown inthe drawing being turned outwardly. The shims 3 may either be placedbetween each blank 2 or between every second blank 2 which should beopposed to each other, as is apparent from FIG. 6. The shims 3 arearranged in such a way that they are inside the outwardly turned sidesof the blanks 2. The shims 3 may cooperate with a groove 26 in the frameside, which permits displacement of the shims 3 but prevents the shims 3from inclining relative to the plane of the frame 1.

The present invention allows rational machining of large series ofblanks 2. For this purpose use can be made of large or small frames 1.The various working moments are carried out in successively arrangedworking machines, and the frames 1 with the blanks 2 are transferredbetween the different machines on roller conveyors or like conveyingmeans. However, the invention may also be used for small series, inwhich one and the same working machine may be used for several workingmoments. Also in this connection the frame 1 is of great importance.

The invention is not limited to that described above and shown in thedrawings but may be modified within the scope of the appendant claims.

I claim:
 1. Apparatus for retaining a plurality of elongated blanks forshanks for carbide tips and the like comprising:a frame having a top anda bottom and defining an opening extending from the top to the bottom toform at least one pair of opposed sides, said frame further having twobranches extending upwardly from said frame along two of said opposedsides so that the end of the frame has a generally U-shapedconfiguration, the width of said branches being less than the width ofthe opposed sides from which they extend, said branches further definingslots along their inner side; a washer member having a top, a bottom,and projections at opposite sides which are adapted to be received inthe slots of said branches, said projections being smaller than saidslots to enable movement of the washer in said frame; and wherebyelongated blanks can be fixedly placed in their longitudinal directionside by side inside the frame opening and be held therein, but can beaccessible from both the top and bottom of the frame through the frameopening without reorienting the blanks from their held position, andwherein the blanks can be accessible from said frame bottom even whensaid blanks are recessed inwardly of the branch ends when the washer isnot received in the slots, but wherein the washer fills the spacebetween the recessed blanks and the end of the branch ends when thewasher is received in the slots.
 2. Apparatus for retaining as claimedin claim 1, wherein the frame has a generally rectangular shape with twopairs of opposed parallel frame sides.
 3. Apparatus for retaining asclaimed in claim 1, wherein the frame has a generally rectangular shapewith only three coherent frame sides, two of which are opposed andparallel.
 4. Apparatus for retaining as claimed in claim 1 wherein theframe is made of magnetic material.